A variety of operating processes and devices are known in which semifinished products, which are transported in the direction of their longitudinal axis or transverse to it, are guided to a storage area and, corresponding to the requirements of the subsequent processes, can be brought to a heated furnace in which they are heated to a subsequent process temperature and then are fed to the appropriate processing site.
The continuous casting heat of the semifinished product coming from an continuous casting device can be utilized in a further process. A path upstream of the subsequent process can be provided in such manner that the partially finished product is not cooled to the storage temperature but is fed to the heating oven of the rolling unit or heating device arranged upstream of the rolling unit.
When the semifinished product (e.g. slabs to be further rolled, or billets or blooms) of the continuous casting unit is taken away continuously at a fixed rate, the rate at which the rough-shaped articles are available may not be suited for the further processing speed and the further processing time of the finishing deformation operation and further processing stations and, buffer storage are usually associated with the heating furnace and can be provided between it and the continuous casting device, with which the different capacities based on the differences in the initial and subsequent processing speeds are matched (German Open Patent Application 27 23 626).
It is also known to use, in a sense, the continuous casting heat of the semifinished product by transferring such heat to the already cooled and even not semifinished product by providing them together in one and the same heating furnace. This shortens the heating time to a desired subsequent processing temperature or permits the heated semifinished product to remain in the furnace for a shorter time than the cold product.
This interdependence between the continuous casting device and the subsequent processing unit makes it difficult to adjust the components of the total unit, such as the deforming (e.g. primary rolling) device, after-heating unit, and buffer storage with respect to one another.
In practical operation, frequently cold products from storage areas are introduced to the heat-transferring furnace so that the semifinished product fed to the subsequent rolling unit cannot be removed from the furnace in requisite numbers.
The processing of semifinished products having a variety of dimensions requires an expensive program plan and control of the steel plant, the continuous casting device and the subsequent processing device. Even where computer control is available to establish such programs the entire unit is not very flexible when products of different dimensions should be produced in fewer or larger numbers of pieces. An additional disadvantage is that the individual components of the entire unit are not driven independently of each other but must be driven jointly so that in part increased empty run times are unavoidable. Also the storage requires an increased organizational expense.
Attempts, for example with high quality steel rolling with conventional rolling programs using known working processes, using the previously described approach with heat transfer between hot and cold semifinished products allows a more or less direct pass through of the semifinished product to make up only 20 to 30% of the total output of the finishing rolls.
Besides these difficulties and disadvantages which accompany the use of the known working processes, it is frequently necessary that the semifinished product be inspected and, if necessary, cleaned in the subsequent processing in a still heated state instead of in a cooled condition on its path or in the storage areas.